1. Field of the Invention
The present invention relates to image recording apparatuses such as a printer, facsimile machine, and copying machine, particularly to a recording sheet in which distortion of an image recorded by an image recording apparatus using a plurality of recording heads to increase a recording width is corrected and to image recording apparatus using this recording sheet.
2. Description of the Related Art
An image recording apparatus of a photosensitive recording system, thermal transfer recording system, ink jet recording system or the like has been used in image recording apparatuses such as a printer and a copier machine. A recording head in which a large number of recording devices for recorded dots are linearly arranged at equal intervals is used in these recording systems.
Preparation of a recording head having a large recording length has a problem that yield becomes worse and cost increases with a larger length, and it has been proposed that a recording width be extended using a large number of recording heads. For example, in Jpn. Pat. Appln. KOKAI Publication No. 6-255175, a method has been described in which a plurality of recording heads are linearly arranged in such a manner that end portions of the heads overlap with each other to a certain degree. A position from which the recording head is to be switched in supplying an image signal to each recording head is irregularly set for each scanning line with respect to a region where the recording devices are redundant, so that joints become inconspicuous and the recording heads are easily arranged.
Moreover, in Jpn. Pat. Appln. KOKAI Publication No. 10-115955, a method and an image recording apparatus have been described in which to form a color image by a plurality of recording heads, a positional shift of each recording head is corrected to obtain an image having a satisfactory image quality from Moire fringes produced by superimposing test patterns formed by the respective recording heads.
Furthermore, in Jpn. Pat. Appln. KOKAI Publication No. 2000-25214, a method is described in which synchronization is controlled in a case where a width direction of a page is divided to perform printing by a plurality of recording heads.
According to conventional art, positional shifts of recorded dots of different colors printed in the same position of a recording sheet, and positional shifts of recorded dots of connection portions between recording heads adjacent in a width direction can be corrected. However, when a plurality of recording heads are connected to each other to expand a recording width, and arrangement of dots recorded by the respective recording heads shifts from a straight line, the recorded image is also distorted, but this cannot be corrected.